What is manganese?
Manganese is a trace element, a metal that is an essential nutrient to human health .
The chemical symbol for manganese is Mn.
- Antioxidant activity
- Synthesis of glucose from non-carbohydrate molecules (gluconeogenesis)
- Removal of excessive ammonia from the body (urea cycle)
- Synthesis of collagen, which is important for bone strength and proper wound healing
- Synthesis of proteoglycans, needed for cartilage and bone strength
- Reference: 
- PLANT FOODS: raisin bran cereals, brown rice, oatmeal, spinach, pineapple, nuts 
- ANIMAL FOODS are usually not a good source of manganese.
- Drinking water may contain 1-100 mcg manganese/liter, usually less than 10 mcg/liter.
- Human breast milk contains 3-10 mcg manganese per liter, which is enough to meet the needs of infants 0-6 months of age .
Chart 1. Foods High in Manganese
|ANIMAL FOODS||Manganese (mg)|
|Mollusks, mussels (3 oz, 85 g)||6|
|Fish, bass, burbot, pike, trout (3 oz, 85 g)||0-7-0.9|
|Liver (3 oz, 85 g)||0.1.-0.5|
|Chocolate, dark (1 oz, 28 g)||0.5|
|Teff (1 cup, 237 mL)||7|
|Raisin bran cereal (1 cup, 237 mL)||0.8-3|
|Pine nuts (1 oz, 28 g)||2.5|
|Brown rice (1 cup, 237 mL)||2.1|
|Spaghetti, whole-wheat (1 cup, 237 mL)||1.9|
|Soybeans (1/2 cup, 120 mL)||1.8|
|Spinach, cooked (1 cup, 237 mL)||1.7|
|Pineapple (1 cup, 237 mL)||1.5|
|Instant oatmeal (1 cup, 237 mL)||1.3|
|Bread, whole-wheat (2 slices, 50 g)||1.2|
|Collards (1 cup, 237 mL)||1.1|
|Sweet potato (1 cup, 237 mL)||0.9|
|Okra, cooked (1/2 cup, 120 mL)||0.9|
|Blackberries (1 cup, 237 mL)||0.9|
|Tea, various types (1 cup)||0.5-0.9|
|Almonds, peanuts (1 oz, 28 g)||0.7|
|Sunflower seeds without hulls (1 oz, 28 g)||0.6|
|Beans: pinto, lima, navy; lentils (1/2 cup, 120 mL)||0.4-0.5|
|Potatoes, cooked (1 cup, 237 mL)||0.2|
Chart 1 source: USDA.gov  All listed foods are ready to eat.
How much manganese do you need?
According to the Institute of Medicine (IMO) in the U.S., the Adequate Intake (AI) for manganese for adult men is 2.3 mg/day, and for women 1.8 mg/day .
Manganese deficiency, which is not common, can result in skeletal abnormalities, impaired growth, slow wound healing, decreased blood cholesterol levels, impaired glucose intolerance and skin rash .
Non-prescription (OTC) oral manganese supplements:
- Manganese gluconate, manganese sulfate and manganese ascorbate
- Manganese as part of multivitamin/mineral supplements
- Manganese in combination with chondroitin sulfate and glucosamine hydrochloride
Benefits of Manganese Supplements
Manganese supplements are EFFECTIVE for preventing or treating manganese deficiency .
There is INSUFFICIENT EVIDENCE about manganese effectiveness in prevention or treatment of premenstrual syndrome (PMS), anemia, osteoporosis, osteoarthritis, diabetes or epilepsy [1,2].
Manganese Safety: Side Effects, Toxicity
The Tolerable Upper Intake level (UL)–the amount that should not cause side effects–for manganese for adults is 9 mg/day .
Manganese in high doses may cause serious side effects, such as tremor resembling Parkinson’s disease .
One investigation has shown that 10 years old children ingesting 800 mcg of manganese per liter of drinking water had lowered intellectual capabilities . The US Environmental Protection Agency (EPA) recommends 50 mcg/liter as the maximum allowable manganese concentration in drinking water. Manganese toxicity from food has not been documented so far. Newborns, children, and individuals with liver disorders and iron deficiency may be more susceptible for manganese toxicity [1,2]. If you intend to use manganese during pregnancy or breastfeeding, speak with your doctor about the appropriate dose.
Manganese Interactions With Drugs and Foods
Manganese may decrease the absorption and effect of certain antibiotics (ciprofloxacin, demeclocycline, minocycline, tetracycline), so take manganese supplements and antibiotics at least two hours apart .